1. Field
Embodiments of the present invention relate to a bearing housing, a water tub for a washing machine, which is formed by injection molding under the condition that the bearing housing to install bearings is inserted into the water tub, and a manufacturing mold unit of the water tub.
2. Description of the Related Art
In general, a washing machine is an apparatus that repeats courses, such as washing and rinsing courses, to wash laundry, and includes a water tub to contain water, a drum rotatably installed in the water tub, and a driving motor to generate rotary force to rotate the drum.
The driving motor includes a rotary shaft passing through the water tub to transmit rotary force to the drum, and bearings to rotatably support the rotary shaft and a bearing housing, on which the bearings are installed, provided with a shaft installation hole passing the rotary shaft are installed on the tub. Generally, the bearing housing is installed under the condition that the bearing housing is inserted into a water tub manufacturing mold unit in the injection molding process of the water tub and thus is buried under the water tub.
The above water tub manufacturing mold unit, to manufacture the water tub by injection molding under the condition that the bearing housing is inserted into the water tub, includes a first mold and a second mold, which are connected to form a cavity having a shape corresponding to the water tub therebetween. The bearing housing, which is manufactured in advance, is inserted into the cavity, and then a molten resin is injected into the cavity, thereby completing the manufacture of the water tub.
In the process of injecting the molten resin into the water tub manufacturing mold unit, the bearing housing moves due to pressure applied to the molten resin, and thus is rotated or inclined, thereby generating a defect of the water tub.